Gateway Storage Company Ltd plans to build an underground natural gas storage facility in the East Irish Sea, approximately 25 km (15 miles) offshore, south west of Barrow-in-Furness. Storage caverns will be developed in a natural salt structure below the seabed and will enable gas to be delivered, stored and then returned to the UK's national transmission system. The offshore gas storage facility will provide a significant boost to the security of energy supply in the UK gas market and will help to meet the strategic energy policy objectives of the UK government. When completed, the caverns will have a working gas storage capacity of 1.52 billion standard cubic metres (~562 million therms), adding nearly 30% to the current UK gas storage capacity.